Carburetor



Jan. 9, 1934. R. E. MacKENzlE 1,943,082

GARBURETOR I Filed Jan. so, 1952 3 sheets-shed 1 Jan. 9, 1934. R. E. MacKENzlE CARBURETOR Filed Jan. .'50, 1932 5 sheets-sheet 2 `lam. 9, 1934.

R. E. MacKENzlE CARBURETOR 3 Sheets-Sheet 5 Filed Jan. 30, 1932 za G1 Y 29 49 INVENToR /AA'Q ATTORNEY lll Mn' Patented Jan. 9, 1934 UNITED sTATi-:s

1,943,082 CARBUBETOB Russell E. MacKenzie, lletroit, Mich., assignor to Detroit Lubricator Company, Detroit, Mich., a

corporation of Michigan Application January 30, 1932. Serial No. 589,317`

1o claims. l(C1. 2er-49) M provements in carburetors, and more particularly to a carburetor for use with or for supplying fuel to an internal combustion engine.

An object of my invention is to provide a carburetor in which the throttle or' other fuel mixture dow controlling means will be automatically regulated or adjusted to the positions for maximum efliciency for certain given air to fuel ratios without affecting the normal operation of the controlling means.

The invention consists in the novel construction and combination of parts, to be more fully described hereinafter, and the novelty of which will be particularly pointed out and distinctly` claimed.

In the accompanying drawings to be taken as a part of this specification, I have fully and clearly illustrated a preferred embodimentof my invention, in which drawingsf Figure 1 is a view in side elevation of a carburetor embodying my invention, and having a portion of the side wall broken away to show the internal construction;

Fig. 2 is a view in end elevation looking from left to right of Fig. 1, and partly in section on the line 2-2 thereof;

Fig. 3 is a detail top plan view on the line 3-3 of Fig. 2, showing the normal relative positions of certain of the buretor reversed from the position of Fig. l;

Figs. 4 and 5 are detail views similar to Fig. 3, but showing other relative positions of the elements, namely, a warming-up and a starting position respectively;

Fig. 6 is a view in reduced size and partly in vertical central section, taken transversely to Fig` 1 to show the air control varies;

Fig. 7 is an enlarged detail view, taken on the line 2-2 of Fig. l, and

Fig. 8 is a diagrammatic view in section, showing the relation of the ports and passages.

Referring to the drawings by characters of reference, l designates, generally, the hollow casting or body of a carburetor having a passageway 2 therethrough defining a mixing chamber or passage having a main air inlet 3 and a mixture outlet 4. The inlet 3 is preferably separated from the mixing chamber by cooperable and separable valve plates or vanes 5 having cooperating edge recesses deilning a primary air flow port 6. Within the passageway there is a vertical fuel nozzle 7 operatively connected to the vanes 5 for reciprocation thereby by lever arms (not shown) which engage in the nozzle elements, but with the car-l I ential groove or 'recess groove or recess 7, and having an adjustable metering pin 8 controlling the dischargev of fuel from the nozzle.- The nozzle is supplied through a passage 9 with fuel from a constant level float chamber or reservoir 10 having a fuel inlet 10a controlled by a float operated valve (not shown), the same being well known in the art. The outlet from the mixing chamber is controlled by a throttle valve 1l, preferably of the butterfly type, xed on a shaft 12 journaled in the side walls of the casing 1. One end of the shaft l2 projects through the casing and has fixed thereon above the reservoir an operating lever 13 having arms 14, 15 extending opposi ely from the shaft.

On the casing 1 there is a lateral, ,substantially vertical extension 16 positioned below the pro-y jecting throttle shaft end and above-the reservoir. The extension 16 comprises a valve casing having a substantially vertical cylindrical bore 17 therethrough. A conduit 18 extends or opens from the bore 17, as at 19, through the extension and casing walls and opens or discharges into the passageway 2 above or on the outlet side of the throttle at a port 20. A conduit 21 extends or opens from the bore 17, as at 22, at a point spaced circumferentially from conduit opening 19, and discharges through a nozzle 23 which projects substantially radially into the passageway 2 below or on the inlet side ofthe throttle and above the vanes. A cylindrical valve member 24 is fitted ,for rotation in the bore 17, project-ing above and below the extension 16, andls held against endwise or vertical movement by a screw 25 or the like which seats in a circumfer- 26 in the valve member. Within the valve member 24 there is a cylindrical fluid chamber 27 having a concentric pasage or aperture 28 through its bot'jom wall, the passage opening intoa concentric cylindrical cavity or recess 29 in the lower end of the valve member. The top of the chamber 27 is closed by a freely reciprocable close fitting cylindrical valve plug 30 which is connected-by a link or push rod 31 to the lever arm 15. if Depending from and fixed to the plug valve 30 there is a hollow plunger or piston Vrod 32 which extends downward with a close but free sliding fit throughl yaperture 28 and terminates in the oat chamber 10. A cover member 33 is provided for chamber 10 and has an aperture therethrough surrounding rod 32 and through which a pump cylinder casing 34 de pends, the casing having a lateral flange 35 which rests on the member 33 to support the casing 34 therefrom. Through the bottom wall of the casing 34 which terminates adjacent the bottom I the which engages Athe rod 32 for reciprocation theree piston is held in engagement with and forced to follow the rod 32 by a compression spring 41.y The bottom end of the recess 29 is or more ports 49 adjacent the bottom ol' the recess. Y

Through the vertical slde wall of the valve is a port 50 which is normally of passage 28.

The free end of lever arm 14 has or carries an adjustable abutment 58, such as a screw, or like, which is cooperable with the casing 16 to limit closing movement of the throttle valve,

is provided with 'a cam means accessible through the casing-edge recess. cam is preferably formed by external surface of the valve member adjacent its substantially at the external surface of the cylindrical valve cover 44 rmly in -off point 62 'and will follow the cam face 60 and move inward under thev force of the spring 41, which acts through link 31 and the lever 13 and until the stop arm 63 strikes stop 65, as in Fig. 5. The throttle valve 11 will now have been moved, due to movement of pin' 61, toward closed position from the line b to the position indicated by the line c, which is the throttle position which will result in maximum carburetor efficiency for the full choke position and for the ratio of air to fuel which follows the closing of air inlet port 50 and the opening of fuel discharge port 54 to feed passage 18.. If the engine is now turned over or cranked, some fuel will be drawn from the main nozzle 7 and be mixed with air admitted at port 6, which mixture will pass the throttle valve which has been automatically opened to the intermediate position indicated by the line c and'be supplied to the engine cylinders. The fuel mixture passing the edge of the throttle will pick up or entrain the solid liquid fuel supplied direct from reservoir 10 via p ort 36, conduit 40, chamber 27, port 54, passage 18, and be discharged from port 20 above the throttle into the passing mixture stream to supply the desired rich mixture for engine priming or starting. When the engine fires and is started, thelever 45 may be and preferably is immediately returned, or permitted to return, under the force of spring 67 in a counter-clockwise direction, except in extremely cold weather, to the position of Fig. 4. As will be noted, movement of valve member 24 from the position ofFig. 5 to that of Fig. 4, causes the cam face to act on the pin 61, forcing the pin outward against the force of spring 41, and in moving the pin moves the throttletherewith toward open position and to the position indicated by line sb. When the throttle edge moves to point b the valve ports 54 and 50 will remain closed, and port 55 -will be brought into register with the nozzle conduit 21. In addition to the mixture of fuel and air discharged into the mixing chamber from the main inlets, there will now be a supplemental discharge of solid-liquid fuel from the nozzleV 23, which will mix with the main mixture and passing the open throttle valve will be fed to the engine cylinders. It is to be noted that with the throttle edge at the point b', the engine suction will be sufficiently transmitted to the vanes 5 to cause them to open somewhat, which will lift the main nozzle 7 relative to the valve 8 and so maintain a desired fuel ratio from the main air and fuel inlets, but this mixture ratio will not be rich enough in fuel for warming' up the engine, so the deficiency in fuel is made up by the supplemental discharge from the nozzle 23, which is, however, less than the prior discharge from conduit 13. By providing the cam faces 59 and 60, which are operative to move the throttle to dierent positions, itis possible to automatically obtain the proper and most advantageous throttle positions for predetermined fuel to air ratios for engine starting and warming up. As the valve member 24 is moved from normal to the position of Fig. 4, thus causing a discharge of fuel through nozzle 23, the quantity of fuel supplied will be increased, thereby decreasing the ratio of air to fuel. When the valve member is moved from the position of Fig. 4 to that of Fig. 5, the fuel now discharged through the larger priming passage 18 will be further in!- .passageway therethrough, means creased, thereby further decreasing the ratio of air to fuel.

When the engine has been warmed-up, the lever 45 will be returned to thepositon of Fig. 3, which will permit the throttle to move under the force of spring 41 to normal idling position 50 and 53, but port 53 will not supply fuel tothe nozzle 23 as the suction thereon will be satisfied by the economizing air admitted to chamber 27 through port 50. As the throttle is gradually opened by lever 13, the plug valve 30 will finally cut down and close off port 50, thereby placing the fuel in the reservoir under the mixing chamber suction through nozzle 23 and causing a supplemental discharge of fuel, which, however, will be diluted by air entering the bleed port 57, which will have been moved into recess 29. Upon a quick movement of the throttle to open position, the piston 38 will force fuel from the pump chamber up the tube or conduit 46 into chamber 27 and thence through nozzle 23 to the mixing passage 2. Some of the fuel entering chamber 27 will be forced out or overiiow through air inlet ports 5G, 51 into the cup 47. This over- 100- fiowing fuel will drain through passage 48 into recess 29 and enter port 57 to prolong the discharge of fuel from nozzle 23 and augment the supplemental supply which occurs when the port 56 is closed by plug valve 30, structure or feature,

vention.

The sizes and dimensions of ports and passages heretofore'defined arevparticuiarly adapthowever, is not of my ined, though not limited, for use in a carburetor 11o having a mixing passage diameter of about one and one-half inches and a main nozzle jet or port diameter of about sixty-seven thousandths (0.067) of an inch.l

esv

which follow-up What I claim and desire to secure by Letters M5 Patent of the United States is:

1. .d carburetor comprising a casing mixing passage with an to supply fuel to said having 8; A

passage, a throttle conair inlet thereto, means trolling flow through said passage, means to regulate the fuel-air ratio in said passage, and means operatively connecting said regulating means and said throttle, said connecting means including means acting upon a decrease in the ratio of air to fuel to move said throttle toward an open position and including means acting upon a further decrease in the ratio of air to fuel to move said throttle toward closed position.

2. In a carburetor, a casing having a mixture to said passageway, means controlling said supply means and being operable in one position to eect a predetermined supply of fuel and in another position to effect 'a predetermined increased io supply fuel 13o supply of fuel, means to control flow through said passageway, and means responsive to operaion of said rst-named control means to move said second-named control means toward an open position'as said niiet-named control means takes said one position and named control means toward closed position as said rst-ned conrol means takes said other position.

3. In a carburetor, a casing having a mixture then to .move said second- Mo passageway therethrough, means to supply fuel M5 to said passageway, valve means controlling the discharge of fuel into saidpassageway, said valve means being operable'in one position to permit a predetermined discharge of fuel and beine: op erable in another position to rmit a predetto said other position. Y through said passageway, means to control the l 4. In a carburetor, a casing having a mixture fuel supplied by said flrst-named means, means 85 passageway therethrough, a throttle controllingy operatively connecting said second-named and said passageway, a main fuel nozzle to supply fuel said third-named means, said connecting means to said passagewa a fuel reservoir, a conduit including means to aotuate said second-named communicating with said reservoir and dischargmeans to increase ow through said passageing into said passageway, a valve controlling said way upon operation of said third-named means 9,0 conduit, said valve having a port 0f predeterto increase the fu'el supplied to said passageway, mined cross-Sectional area and having a SeCOnd and said Connecting means ineluding means t0 move Said throttle toward Open DOSOH D011 named means is actuated to increase further 95 i5 Said Cnnecting manS including means acting operaiively connecting said passageway control- 110 to mOve Said throt'le tOWard Open DOSitiOn when ling means and said cam means, said cam means said valve means is moved t0 permit discharge acting upon movement of said valve member to 40 closed position when said valve means is moved means to increase 110W through Said passage- 115 5o por's and discharging into Said mixing passage, means, a throttle valve eentreuing new through 125 upon movement of said valve member in one dian mixing passage therein, a throttlecontrolling ow Charge of fuel the' {1l-gh Paint between said 

